Suspended gyratory centrifugal



Oct. 3, 1950 c, o cQ'r 2,524,678

- SUSPENDED GYRATORY CENTRIFUGAL Filed Aug. 15, 1947 2 Sheets-Sheet 2 INVENTOR. 0/4215 A. OLqorT 81 0/4171 I [aims- ATTOiQ/VEY Patented Oct. 3, 1950 VUNITED STATES PATENT OFFICE SUSPENDED GYRATORY CENTRIFUGAL Charles A. Olcott, West Milford, N. J.

Application August 15, 1947, Serial No. 768,911

3 Claims.

This invention relates to sugar centrifugal machines and more specifically to suspended gyratory centrifugals.

In many well-known types of centrifugals for drying sugar and the like, the basket holding the magma is suspended from an overhead bearing leaving the lower part of the suspended mechanism free to revolve around its own center of gravity which may be laterally displaced from the geometric center of the machine. The purpose of this is to permit a slightly unbalanced load to rotate at high speed without imposing excessive strains on the bearing. While this construction is desirable for high speed running, it is also desirable to have the machine held in central position while rotating at low speed through the loading and unloading operations. In loading it sometimes happens that more material falls into one side of the basket than into the other, and this causes the basket to swing in a relatively wide angle from the vertical, due to this unbalance, but a relatively small force will hold the basket centrally located and cause the load to distribute itself evenly around the basket, and thus be suitably balanced for high speed running. Also during the unloading operation in the case of hard sugar, the basket may be pushed to one side and against the curb if it is allowed to hang free, but it can be held in a vertically central position by a relatively small force.

It is an object of this invention to provide in sugar centrifugal novel and improved means for restraining the basket to a vertically central position during the rotation thereof at low speed.

It is another object of the invention to provide restraining means of this type which is simple in construction and in operation and which is effective during both the loading and unloading operations.

It is still another object of the invention to provide novel and improved means for restricting the vertical suspensory shaft for the centrifugal position which means can be automatically released when the speed of the basket exceeds a predetermined value.

In accordance with the invention, these and related objects are attained by providing in an illustrative embodiment a pair of clamping members placed on opposite sides of the vertical shaft supporting the centrifugal. The clamping members are moved toward and away from one another by an elliptical cam contacting the ends of the clamping members farthest removed from the shaft. The cam rotation is controlled by a piston rod connected to an air cylinder. When the centrifugal is at rest or rotating at low speed, air pressure is applied to the cylinder and the cam is rotated so as to bring the clamping members toward one another, thus restricting the rotation of the shaft to a central position; but when the centrifugal is rotating at ahigh speed, the air pressure is released and the cam is rotated in a direction to move the clamping members away from one another, thus permitting the basket to swing out as far as the curb.

The invention will be more readily understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which:

Fig. l is an elevation view, partly in cross-section, of a centrifugal basket and driving means therefor provided with means in accordance with the invention for holding the basket in a central position while the basket is rotating at slow speed;

Fig. 2 is a plan view of the centrifugal basket and a portion of the clamping means shown in Fig. 1 for holding the basket centrally positioned at slow speed, the clamping means being shown in theoperating (low speed) position;

Fig. 3 is an enlarged plan View, with parts in cross-section, of a portion of the arrangement of Fig. 2, the clamping means being shown in the non-operating (high speed) position; and

Fig. 4 is an elevation view, with parts in crosssection, of a portion of the apparatus shown in Fig. 3.

Referring more specifically to the drawings, Fig. 1 shows, by way of example for illustrative purposes, a sugar centrifugal I0 having an arrangement in accordance with the invention for maintaining the basket in central position while it is rotating at slow speed. The centrifugal comprises a rotatable vertical shaft or spindle ll adapted to be driven by any suitable means such as an electric motor l2 mounted above it. Suspended from the spindle is a perforated basket I3 having a stationary outer casing or curb I4. For simplicity in the drawings, the perforations have not been shown. This curb has a cylindrical side wall 15, a top t6 and a bottom I! which can be provided with a suitable annular trough or troughs IE to carry away, in a manner well known, the various liquids ejected from the basket I3 during the centrifuging process. The centrifugal machine is provided with the usual charging and discharging equipment but for simplicity in the drawings these have not been shown. As described hereinafter, the centrifugal machine also includes means for restraining the rotation of the basket to a central position at low speeds.

Slidably mounted on the curb or casing [4 are two clamping members l9 and 29 held in a suitable guide 2| which is fastened to the top It of the curb. The members I9 and have remote end portions 22 and 23, respectively, between which is placed an elliptical cam 24. The cam is mounted on the guide 2| in such a way that it can be rotated when the lever 25, to which it is fixedly attached, is rotated. This lever is connected by means of a pin 26 to the piston rod 21 of an air or other type of cylinder 28 which is supported on a suitable bracket 29 attached to the top I6 of the curb or casing.

The cylinder 28 has air applied thereto by means of an air line 30 which is connected to the solenoid-operated, 3-port valve 3| of any wellknown type, such as that described in Patent 2,254,383 issued September 2, 1941, to C. A. Olcott, for example. The valve 3| has one port 32 connected to the pipe 30, a second port 33 connected to a source (not shown) of compressed air and the third port 34 connected to a vent pipe 35. The valve 3| has a piston which operates between an upper position in which compressed air is applied from the source through port 33, the valve 3| and the port 32 to the pipe 39 and a lower position in which air from the source is cut off by the valve and the pipe 33 is connected through the valve 3| and the port 34 to the vent pipe 35. When the air is vented from the cylinder 28, the iston 36 therein is moved toward the bracket 29 (against the air pressure) by the spring 31.

The valve 3| is moved to its upper position to admit air into the cylinder 28 to move the elliptical cam 24 into the position shown in Fig. 2 by the energization of the solenoid 38. This is accomplished by the completion of a circuit including a suitable source of electromotive force such as the battery 39, the line 40, brush 4|, commutator 42 connected by means (not shown) to spring 43 which has mounted on the inside thereof a contact 44, contact 45 mounted on the shaft H (but insulated therefrom) and which is connected by a wire (not shown) to contact 46 on the outside of guard 41, brush 48, line 49, and the solenoid 38. The contact members 44 and 45 are in contact when the shaft H is at rest or rotating at low speed but break contact when the speed exceeds a predetermined amount, this action being facilitated by the ball 53 on the end of the spring 43 which ball is flung outwardly by centrifugal force when the speed increases. Of course, any other suitable means for energizing the solenoid at low speed and deenergizing it at high speed can be used instead of the arrangement shown. Such an alternative means can be the speed responsive mechanism shown in Fig. 4 of the above-identified Olcott patent arranged to operate a relay which opens when the centrifugal switch is closed, and vice versa.

The operation of the arrangement shown in Fig. 1 will now be described, reference bein also made to Figs. 2, 3 and 4. Figs. 3 and 4 show the condition of the apparatus at high speed while Figs. 1 and 2 show it at low speed. At high speed, the solenoid valve 3| is deenergized, the cylinder 28 is in its retracted position because of the action of the spring 31, the cam 24 is in the position shown in Fig. 3 and the members l9 and 20 are separated, being held apart by the action of the spring 5| and disengaged from shaft l, leaving a space between these members and the shaft large enough so that the basket may swing to an amount indicated by the distance between the members l3 and M in Fig. 4 at which point the basket hits the curb, thus limiting its angular swing. In other words, the basket can swing as far as the curb wall l4 will allow it without causing the shaft H to touch either the member l9 or 20. When the machine slows down to a speed of, for example, 150 R. P. M. or less in a 40 inch centrifugal machine, the solenoid 38 is energized by the completion of the electrical circuit shown in Fig. 1 by the touching of the contact members 44 and 45. The solenoid valve 3| is energized, air passes to the cylinder 29 causing lever 25 to be swung nearly degrees, forcing (by the turning of cam 24) member 20 forward and drawing member 19 backward so that these two will clamp the spindle II and hold it in the central position shown in Figs. 1 and 2. Preferably members l9 and 20 are faced with a self-lubricating material at the points where they engage the spindle Thus at low speed (including both loading and unloading operations) the spindle or shaft is held in a central position, and at high speed it is released so that the basket can rotate around its own center of gravity.

A hook 52 is provided for hanging the usual basket valve which is raised to permit the discharge of the sugar.

Various changes can be made in the embodiment described above without departing from the spirit of the invention, the scope of which is indicated by the appended claims.

What is claimed is:

1. A centrifugal machine for the separation of sugar from sugar bearing materials comprising a suspended gyratory basket, a casing surrounding said basket, a vertical shaft for supporting and rotating said basket, a clamping member adjacent a portion of said shaft above said basket, support means, attached to said casing and forming a support for said clamping member, for guiding the movement of said clamping member from a first position out of contact with said shaft, even at points reached by said shaft at its maximum swing from its central position, to a second position in contact with said shaft at which second position of the clamping member the latter restrains the movement of the shaft and basket to a central position, a pair of contacts cooperating with said shaft to be rotated at a speed proportional to the speed of the shaft and positioned to be closed when the shaft speed is less than a predetermined amount which is much less than full speed, an electric circuit element adapted to be operated when said contacts are closed, and means including a piston controlled by the operation of said electric circuit element and a movable element controlled by said piston for moving said clamping member from said first to said second position and for maintaining it in said position as long as said contacts are closed.

2. A centrifugal machine for the separation of sugar from sugar bearing materials comprising a suspended gyratory basket, a casing surrounding said basket, a vertical shaft for supporting and rotating said basket, a clamping member including a pair of clamps respectively positioned on opposite sides of a portion of said shaft above said basket and adapted to be moved together in opposite directions, support means, attached to said casing and forming a support forsaid U clamping member, for guiding the movement of said clamping member from a first position out of contact with said shaft, even at points reached by said shaft at its maximumu swing from its central position, to a second position in contact with said shaft at which second position of the clamping member the latter restrains the movement of the shaft and basket to a central position, means including an elliptical cam located between portions of said respective clamps remote from said shaft for moving said clamping member from said first to said second position, and means, responsive to the speed of said shaft only when it is rotating at a speed less than a predetermined amount which is much less than full speed, for rotating said cam so that the clamping member is moved to said second position and held in such position as long as the speed of the shaft is below said predetermined speed, 3. A centrifugal machine for the separation of sugar from sugar bearingmaterials comprising a suspended gyratory basket, a casing surrounding said basket, a vertical shaft for supporting and rotating said basket, a clamping member including a pair of clamps respectively positioned on opposite sides of a portion of said shaft above said basket and adapted to be moved together in opposite directions, support means attached to said casing and forming a support for said clamping member, for guiding the movement of said Clamping member from a first position out of contact-with said shaft, even at points reached by said shaft at its maximum swing from its central position, to a second position in contact with said shaft at which second position of the clamping member the latter restrains the movement of the shaft and basket to a central position, means including an elliptical cam located between portions of said respective clamps remote from said shaft for moving said clamping member from said first to said second position, and means, including apparatus responsive to the speed of said shaft only when it is rotating at a speed less than a predetermined amount which is much less than full speed and an air piston controlled by said apparatus for rotating said cam so that the clamping member is moved to said second position and held in such position as long as the speed of the shaft is below said predetermined speed.

CHARLES A. OLCOTT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 77,017 Elmenhorst et a1. Apr. 21, 1868 80,702 Barr Aug. 4, 1868 1,600,249 Sando Sept. 21, 1926 2,037,655 Roberts Apr. 14, 1936 2,254,388 Olcott Sept. 2, 1941 

